A Fuel Cell is a device that converts the chemical energy of a fuel directly into electrical energy. Unlike steam-powered generator system, the fuel cell does not first convert chemical energy into mechanical energy.

Fuel cells, like electric cells (batteries), have no moving parts. Unlike electric cells, fuel cells use outside materials in producing an electric current. Fuel cells are very efficient in converting the chemical energy of a fuel into electrical energy. However, for most applications they are too expensive to compete with conventional methods of producing electricity. Their main use is on spacecraft and to provide power at remote locations on earth.

The difference between Fuel Cells and Batteries

Fuel cells are similar to batteries in a lot of ways, using chemical reactions to produce electrical energy. Unlike batteries, however, fuel cells don't go dead; as long as a fuel source is available, a fuel cell can continue to produce energy.

A fuel cell uses a fuel, usually hydrogen, and an oxidizer, usually oxygen (or air), to produce direct-current power. A typical fuel cell contains two electrodes, in the form of metallic screens, separated by a material saturated with an electrolyte, such as potassium hydroxide. Hydrogen is supplied to one screen, oxygen to the other. Chemical reactions between the electrolyte and each of the gases creates a voltage between the electrodes. Water is formed as a by-product of the reactions